clockwise vs counter-clockwise

clockwise

adj
  • Moving clockwise; having rotary motion in the manner of a clock. 

adv
  • In a curve or twist corresponding to the movement of the hands of a clock. 

counter-clockwise

adv
  • counterclockwise; anticlockwise 

adj
  • counterclockwise; anticlockwise 

How often have the words clockwise and counter-clockwise occurred in a corpus of books? (source: Google Ngram Viewer )